TransformedBitmap fails with OutOfMemoryException

I use Win7(x64) + FW4.8 + VS2019

In my WPF app I need medium bitmap 2000x2000, which I create by internet sample:

var src1x1 = BitmapSource.Create(1, 1, 72, 72, PixelFormats.BlackWhite, BitmapPalettes.BlackAndWhite, new byte[] { 0xFF }, 1);
var src = new TransformedBitmap(src1x1, new ScaleTransform(2000, 2000));// here I get Exception
cnvMain.Background = new ImageBrush(src);// cnvMain = Canvas

Last call before exception was:
System.Windows.Media.Imaging.TransformedBitmap.FinalizeCreation()

Even having a LOT of memory and x64 app I get this problem - why TransformedBitmap is unable to handle such simple image? It's not heavy in terms of graphics, even x86 app(having 2GB) must easy handle it.